Texas A&M University Bio-Digesters

Texas A&M University owns and operates its own wastewater treatment plant, which receives high strength waste from three tissue digesters used by research labs on campus. The plant had experienced negative operational impacts associated with high-strength effluent from the tissue digesters, including loss of biomass in aeration basins, which is necessary to break down contaminants in wastewater. Also, fats, oils and grease were scaling the ultraviolet system quartz sleeves, reducing their sterilizing effectiveness.

During a two-year period starting in 2021, Stanley Consultants was retained to assess plant challenges, the likelihood of failure by various equipment and the cost of those failures and to present alternatives for improving the facilities and their operation. Most of the wastewater treatment equipment and digester system components were 25 years old and considered past their useful lives.

In addition to asset replacement and upgrades, Stanley Consultants reviewed six solutions to manage and treat high strength wastewater from the tissue digester. Collaboratively Texas A&M University and Stanley Consultants selected mainstream suspended air flotation (SAF®) clarification, by Heron Innovators. This next generation process creates a floc using coagulants and polymer and floats solids with bubbles charged with a surfactant. Instead of dropping to the tank bottom and collected there, the high-strength waste is floated off the surface.

Digester improvements along with planned SAF Facility at the wastewater treatment plant will improve the facility’s overall reliability and resiliency, allowing the plant to sustainably meet its current effluent permit requirements. In addition, these improvements will allow the university to conduct research and operate without wastewater-based restrictions.